Rooftop solar is emerging as the latest threat to South Australia's energy system security, as network operators and suppliers predict that it could soon on some days supply the state's entire energy needs.

It triggered a chain reaction that knocked nine windfarms out of the grid, and cut the state's connection to Victoria's backup power supply.

But as repairs continue, the company that owns the state's power transmission network, ElectraNet, has warned the latest risk to system security is not the weather but rather the anticipated massive uptake in solar and batteries.

It said the state was at its most vulnerable to another blackout event on days of "minimum demand" — when people are using the least amount of power and all of that power is being drawn from solar.

"It could be as early as 2023 when the energy coming from rooftop systems in South Australia is all the electricity that state needs to run the grid," Australian Energy Council chief executive Matthew Warren said.

"While that's interesting, that poses technical challenges in how we keep the grid stable."

Mr Warren represents existing energy suppliers and retailers.

Their challenge is how to pay for a grid that is increasingly being used as a backup, as energy users switch to a mix of solar and batteries.

Mr Warren said it was "an accidental experiment".

"We know we have to decarbonise our energy systems, we know we have to use more renewables — but no-one really planned to get to the levels of renewables that we have in South Australia right now," he said.

SA Government's solution could push more people to solar

Across Australia, trials are underway to explore ways of including battery storage into the future energy mix.

The goal is to reduce the need to spend more on infrastructure, and to increase energy security.

In the short term, that does not reduce the risk of those days of minimum demand, and Mr Warren said the state still needed a secure power source.